1. Institute for Global Health, University College London, London WC1E 6JB, UK
2. MRC Clinical Trials Unit at UCL, University College London, London WC1V 6LJ, UK
3. Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
4. Service of Immunology, Southmead Hospital, Bristol BS10 5NB, UK
5. Faculty of Medicine, Imperial College London, London SW7 2BX, UK
6. Department of HIV, Sexual Health and Contraception, Brighton and Sussex University Hospitals NHS Trust, Brighton BN11 2DH, UK
7. Florey Unit Clinic for Sexual Health, Royal Berkshire Hospital, Reading RG1 5AN, UK
8. Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore